Renderer

Category:

AddIn:

Scope:

Code Snippets:

Supports Material List:

Status Screen Widgets:

License:

Visual Stimuli

Base Elements

Local

yes

Standard EventIDE license

In this article:

Introduction
Key Features
Properties
Assigning Materials to the Renderer
Practical Use

Introduction

The Renderer element is used to display visual materials from the Material Library on the experiment’s stimulus screen. It provides a scalable, transformable viewport for bitmaps, vector shapes, and other visual items, along with a wide range of real-time image processing effects.

Multiple materials can be loaded into the Renderer’s internal list to create stimulus sets for presentation sequences or condition-based display. The element supports spatial transformations (position, rotation, scaling), alpha masking, pixel effects, and positional jitter, all of which can be modified at runtime.

Key Features

Renders images and vector graphics from the Material Library.
Real-time image effects including blur, pixelation, scrambling, and color adjustments.
Alpha masking for transparency-based compositing.
Spatial transformations (position, rotation, scaling) with adjustable pivot point.
Multiple material handling for stimulus sets.
Hardware-accelerated rendering for smooth performance.
Runtime control of appearance and effects.
Integrated with EventIDE’s runtime variable system for adaptive stimulus display.

Properties

Name	Description	Property Class	Type
Material List
Item Count	Return the total number of material items in the list of this element	Status	Int32
Selected Index	Defines an index of the selected library item in the list of this element	General	Int32
Selected Item	Defines a name of the selected library item in the list of this element	General	String
Equalize RGB	If true, the RGB pixel intensity is equalized across all loaded items	Design	Boolean
Visual Appearance
Auto Size Mode	Whether the rendering viewport is automatically resized on loading a new material	General	Int32
Alpha Masking	Whether visual content is used to create an opacity mask on the event surface	Design	Int32
AntiAliasing	If true, the rendered content will be antialiased	General	Boolean
Position	Position of the rendering viewport on the screen	General	clPoint
Size	Size of the element's rendering viewport on the screen	General	clSize
Z Order	Indicates Z Order of the element on the given event	Status	Int32
Pivot Point	Defines alignment of the pivot point relative to element's rendering area	General	stAlig..
Visible	Whether the element is visible	General	Boolean
Rotation	Rotation angle in degrees	General	Double
Effects
Transparent Color	The color in the original pixels to be set as transparent	General	stColor
Transparent Tolerance	Tolerance ratio for transparency color selection	General	Int32
Color Mask	Multiplies original pixels with a mask color for a glass-like effect	General	stColor
Opacity	Opacity of the rendered content	General	Int32
Contrast	Contrast of the rendered content	General	Int32
Brightness	Brightness of the rendered content	General	Int32
Saturation	Saturation of the rendered content	General	Double
Pixelation	Pixelation of the rendered content	General	Int32
Blurring	Radius for gaussian blur in pixels	General	Int32
Scrambling	Proportion of scrambled voxels	General	Double
Scrambling Grid Size	Dimensions of the scrambling grid	General	clSize
Positional Jitter
Reset Jitter Now	Runtime command to reset the positional jitter	Runtime Command	Boolean
Current Jitter	Returns the current jitter	Status	clPoint
Jitter Range	Range for random jitter, centered on element position	General	clSize
Test Jitter	Test the current jitter setting	Design	Boolean
Control
Is Enabled	If set to false the element is completely omitted when the experiment is run	Design	Boolean
Title	Title of the element	Design	String

Assigning Materials to the Renderer

To display visual content, the Renderer must be linked to one or more materials from the project’s Material Library.

Load Materials into the Material Library – Add your images, vector shapes, or other supported formats via the Material Library panel.
Assign Materials to the Renderer – Open the Renderer’s Material List section in the Properties panel and select the desired material using Selected Item or Selected Index.
Switch Materials at Runtime – You can change the material displayed by modifying the Selected Index or Selected Item property during execution, allowing dynamic stimulus changes within a trial.
Apply Optional Preprocessing – Enable Equalize RGB to normalize color intensity across loaded materials, ensuring consistent brightness and contrast.

Practical Use

The Renderer is a flexible building block for visual stimulus presentation. It can be used alone or in combination with other elements such as masks, overlays, or real-time signal-based triggers.

Example usage scenarios:

Static image display – Present a single image for a fixed duration.
Stimulus sequence playback – Cycle through a set of images by updating the Selected Index at timed intervals.
Dynamic visual effects – Apply blurring, color masking, or pixelation in response to experimental variables or participant input.
Masked displays – Use alpha masking to reveal only specific parts of the stimulus area.
Attention and eye-tracking studies – Combine with positional jitter to prevent image location habituation.